Import FEC code from Luigi Rizzo's RMDP

Paper: http://info.iet.unipi.it/~luigi/mccr6.ps.gz
Code:  http://info.iet.unipi.it/~luigi/rmdp980703.tgz

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 31 insertions, 2 deletions

diff --git a/mcast_image.h b/mcast_image.h
index 96aa752..26c675e 100644
--- a/mcast_image.h
+++ b/mcast_image.h
@@ -1,14 +1,16 @@
 #include <stdint.h>
 
-#define PKT_SIZE 1400
+#define PKT_SIZE 1410
 
 struct image_pkt_hdr {
 	uint32_t resend;
 	uint32_t totcrc;
 	uint32_t nr_blocks;
 	uint32_t blocksize;
+	uint32_t block_crc;
 	uint32_t block_nr;
-	uint32_t block_ofs;
+	uint16_t pkt_nr;
+	uint16_t nr_pkts;
 	uint32_t thislen;
 	uint32_t thiscrc;
 };
@@ -17,3 +19,30 @@ struct image_pkt {
 	struct image_pkt_hdr hdr;
 	unsigned char data[PKT_SIZE];
 };
+
+struct fec_parms;
+
+/* k - number of actual data packets
+ * n - total number of packets including data and redundant packets 
+ *   (actual packet size isn't relevant here) */
+struct fec_parms *fec_new(int k, int n);
+void fec_free(struct fec_parms *p);
+
+/* src   - array of (n) pointers to data packets
+ * fec   - buffer for packet to be generated
+ * index - index of packet to be generated (0 <= index < n)
+ * sz    - data packet size
+ */
+void fec_encode(struct fec_parms *code, unsigned char *src[],
+		unsigned char *fec, int index, int sz);
+
+/* data  - array of (k) pointers to data packets, in arbitrary order (see i)
+ * i     - indices of (data) packets
+ * sz    - data packet size
+ * 
+ * Will never fail as long as you give it (k) individual data packets.
+ * Will re-order the (data) pointers but not the indices -- data packets
+ * are ordered on return.
+ */
+int fec_decode(struct fec_parms *code, unsigned char *data[],
+	       int i[], int sz);